Trailers must be correctly balanced and hitched in order to avoid difficulties with handling and maneuverability. Nonetheless, even trailers that have been properly hitched and balanced can sway while traveling along the highway, particularly in windy conditions. Such swaying can be extremely hazardous and presents the risk of a serious accident.
To compensate for trailer sway, a number of sway control devices have been developed. A particularly popular device of this type is manufactured by Reese. The Reese device employs an elongate sway control bar that is pivotally interconnected to a small ball on the ball mount. A bracket is fixed to the A-frame of the trailer. This bracket carries a pair of brake shoes that are sandwiched about the bar. A rotatable handle selectively tightens and loosens the brake shoes against the bar so that the friction along the bar is adjusted. Typically, the brake shoes are tightened to increase friction at times when the trailer is to be pulled at higher speeds. This tightens the connection between the tow vehicle and the trailer and minimizes sway. However, a tight frictional interengagement is not desirable when the tow vehicle is turning at low speeds. In such cases, a tight interconnection between the sway bar and the A-frame of the trailer may prevent the tow vehicle from turning freely relative to the trailer. Because city or other low speed types of driving conditions must be anticipated, the operator cannot fully tighten the connection for high speeds, but must allow for movement at low speeds. This enables the tow vehicle to turn properly relative to the trailer. Such adjustment is not adequate for full sway control at high speeds in high windy conditions. For this reason, many operators install two sway controls--one on each side of the A-frame and hitch head.
Adjusting the friction on the Reese sway control device can present problems. Most significantly, it is fairly easy for the operator to overly tighten the handle. The operator is able to selectively tighten and loosen the handle by number of turns based on experience and advice. No markings are provided to indicate when maximum desired tightening has been achieved. Overtightening the brake shoes against the sway bar to provide for excessive wind conditions can cause the bar to bend or break. Overtightening can also bend the bracket which mounts the brakes to the trailer frame. In either case, the sway control mechanism may be damaged and rendered inoperable.